DOCSLIB.ORG

Advanced Morphometric Techniques Applied to The

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Advanced Morphometric Techniques Applied to The UNIVERSIDAD POLITÉCNICA DE MADRID ESCUELA TÉCNICA SUPERIOR DE INGENIEROS DE TELECOMUNICACIÓN ADVANCED MORPHOMETRIC TECHNIQUES APPLIED TO THE STUDY OF HUMAN BRAIN ANATOMY TESIS DOCTORAL Yasser Alemán Gómez Ingeniero en Tecnologías Nucleares y Energéticas Máster en Neurociencias Madrid, 2015 DEPARTAMENTO DE INGENIERÍA ELECTRÓNICA ESCUELA TÉCNICA SUPERIOR DE INGENIEROS DE TELECOMUNICACIÓN PHD THESIS ADVANCED MORPHOMETRIC TECHNIQUES APPLIED TO THE STUDY OF HUMAN BRAIN ANATOMY AUTHOR Yasser Alemán Gómez Ing. en Tecnologías Nucleares y Energéticas MSc en Neurociencias ADVISOR Manuel Desco Menéndez, MScE, MD, PhD Madrid, 2015 Departamento de Ingeniería Electrónica Escuela Técnica Superior de Ingenieros de Telecomunicación Universidad Politécnica de Madrid Ph.D. Thesis Advanced morphometric techniques applied to the study of human brain anatomy Tesis doctoral Técnicas avanzadas de morfometría aplicadas al estudio de la anatomía cerebral humana Author: Yasser Alemán Gómez Advisor: Manuel Desco Menéndez Committee: Andrés Santos Lleó Universidad Politécnica de Madrid, Madrid, Spain Javier Pascau Gonzalez-Garzón Universidad Carlos III de Madrid, Madrid, Spain Raymond Salvador Civil FIDMAG – Germanes Hospitalàries, Barcelona, Spain Pablo Campo Martínez-Lage Universidad Autónoma de Madrid, Madrid, Spain Juan Domingo Gispert López Universidad Pompeu Fabra, Barcelona, Spain María Jesús Ledesma Carbayo Universidad Politécnica de Madrid, Madrid, Spain Juan José Vaquero López Universidad Carlos III de Madrid, Madrid, Spain Esta Tesis ha sido desarrollada en el Laboratorio de Imagen Médica de la Unidad de Medicina y Cirugía Experimental del Instituto de Investigación Sanitaria Gregorio Marañón y en colaboración con el Servicio de Psiquiatría del Niño y del Adolescente del Departamento de Psiquiatría del Hospital General Universitario Gregorio Marañón de Madrid, España. Tribunal nombrado por el Sr. Rector Magnífico de la Universidad Politécnica de Madrid, el día ___ de ________________ de 2015. Presidente: __________________________________________ Vocal: __________________________________________ Vocal: __________________________________________ Vocal: __________________________________________ Secretario: __________________________________________ Suplente: __________________________________________ Suplente: __________________________________________ Realizado el acto de defensa y lectura de la Tesis el día ___ de ________________ de 2015, en la E.T.S.I de Telecomunicación. Calificación: __________________________________ _________________ _______________________________________________ EL PRESIDENTE LOS VOCALES _________________ EL SECRETARIO “Si saber no es un derecho, seguro será un izquierdo” Silvio Rodríguez (El escaramujo) Agradecimientos A unas horas de que este documento se entregue definitivamente lo más simple hubiera sido no escribir agradecimientos y así evitar la posible injusticia de no mencionar a todos los que me han ayudado, de una manera u otra, a llegar hasta aquí. Precisamente, después de este esfuerzo, es evidentemente que podemos sobrevivir unas horas más sin optar por lo simple. Agradecer ante todo a Manolo, primero por la oportunidad que me dio al llegar a España de formar parte de este grupo y segundo por la ayuda que me ha brindado durante estos años en el laboratorio. Agradecer la ayuda para terminar este trabajo y también, y a lo cual doy mayor importancia, por lo que he aprendido acerca del esfuerzo que se debe realizar para mantener a flote un laboratorio del cual, todos los que estuvieron, estamos o estarán, tendremos siempre un recuerdo muy especial. Es una tarea casi quijotesca mantener un grupo así con lo poco valorada que está la investigación actualmente. Además quisiera agradecer a otras dos personas muy importantes para llevar este trabajo a algún lugar. Primeramente a mi “nederlandse vriend” Joost. Sin ti nada de lo que se leerá de aquí en adelante hubiera existido. Gracias por esas discusiones, críticas directas y evidentemente por la amistad que mantenemos. En segundo lugar a Chus, sin la cual hubiera estado perdido durante todo este proceso, especialmente al principio. En el medio y al final también lo hubiera estado, seamos sinceros. Un agradecimiento muy especial a mis padres que siempre me han apoyado y de los cuales cada día me siento más orgulloso. De ellos he absorbido todo lo que he podido para llegar a ser mejor persona. De mi madre he heredado la cordialidad, la facilidad para hacer amigos y el sacrificio, de mi padre el despiste, la despreocupación material y el soltar lo que se piensa. A mis primos y a su camioneta. Mi prima, fruto de la unión de dos personas espectaculares, es, resumiendo, mi hermana mayor. Mi primo, antes que su esposo, es, si no la más noble, una de las personas más nobles de mi planeta. Gracias a ambos por todo lo que han hecho por nosotros y por darme el hermano-primo pequeño (ya sólo de edad) que tengo. Estoy super orgulloso de haber suspendido el examen final de mecánica teórica en 2do año de carrera y espero que el “reggaetón” sea como el asma, que se pasa con la edad. Agradecer también a mis primos “italianos” Belkis, Franco e Illide y a la familia Osvaldos-Ariel-Kenia-Teida de 9na entre F y G. El hecho de ser del Vedado influyó siempre en la baja calidad de juego en la pelota a la mano pero siempre estuve ahí para levantar el nivel. El Cerro es otro “level”. A mi chica por irse conmigo aunque finalmente he terminado viniendo yo. Gracias por la confianza, el apoyo y el amor que me has dado durante todo este tiempo. El venir me ha dado la posibilidad de conocer a tu familia que también, como no podía ser de otra manera, es espectacular. Incluyo a Santi dentro de tu familia porque evidentemente forma parte de ella. Una de las ventajas que tiene emigrar es que conoces mucha gente y muchas de ellas se convierten luego en nuevos amigos. Ahora tengo el doble que hace 7 años. Agradecer a todos ellos el estar siempre ahí y que sepan que yo también estoy aquí para cualquier combate. Agradecer a Velarde, a Erick, al Yaci, a Ramón, al Dani, a los Alejandros (Alejandro Ojeda y Alejandro Fiel), Betty, Rogney, Joost, Sonia, Monzón, Ricardo, Iván Linares, Maricela, Maylen, Yanays, Diamela, Jose Luis, Sandra, Pedrito, Eduardo, Lester, Nelson, Tin, Joelay, Mónica, Ana, Pablo, Javi, Cris, Alex/Sisni, Trajana, Esther, Oscar, Lorena, Fidel, Susana, David, Anabea, Kenia, Kike, Vero, Paula, Inma, Carmen, Iván, Eva, Javi Pascau, Juanjo, Pedro, Evan, María, Chema, Eu, etc, etc, etc … Quisiera finalmente agradecer la suerte de haber podido conocer a una persona increíble. Gracias por todo Santi Reig, nos hiciste mejores. Un honor haberte conocido. ><((((º>`·.¸¸.·´¯`·.¸.·´¯`·...¸><((((º>`·.¸¸.·´¯`·.¸.·´¯`·...¸><((((º> `·.¸¸.·´¯`·.¸.·´¯`·...¸><((((º>`·.¸¸.·´¯`·.¸.·´¯`·...¸><((((º>`·.¸¸.·´ Contents Contents Abstract ............................................................................................................................ v Resumen ......................................................................................................................... vii List of tables...................................................................................................................... ix List of figures .................................................................................................................... xi Chapter 1: Motivation and objectives ............................................................................. 1 1.1. Motivation ............................................................................................................................ 1 1.2. Hypothesis and objectives .................................................................................................... 3 1.3. Outline .................................................................................................................................. 3 Related references ....................................................................................................................... 5 Chapter 2: State of the art in brain morphometry ........................................................ 7 Introduction ................................................................................................................................. 7 2.1. Preprocessing steps in brain morphometry ........................................................................... 7 2.1.1. Inhomogeneity correction .............................................................................................. 7 2.1.2. Image registration and spatial normalization ................................................................. 8 2.1.3. Tissue classification ..................................................................................................... 10 2.1.4. Structure parcellation ................................................................................................... 11 2.1.5. Cortical surface extraction ........................................................................................... 12 2.1.6. Volumetric and geodesic smoothing ........................................................................... 14 2.2. Region of interest analysis.................................................................................................. 15 2.3. Voxel based morphometry ................................................................................................. 15 2.4. Surface based morphometry or vertex-wise analysis ........................................................
Load more

Recommended publications
  • Tool-Use and the Chimpanzee Brain: an Investigation of Gray and White Matter, and a Focused Study of Inferior Parietal Microstructure
    Tool-use and the Chimpanzee Brain: An Investigation of Gray and White Matter, and a Focused Study of Inferior Parietal Microstructure by Laura Denise Reyes A.B. in Psychology, June 2008, Dartmouth College M.A. in Anthropology, May 2011, New Mexico State University M.Phil in Hominid Paleobiology, June 2013, The George Washington University A Dissertation submitted to The Faculty of The Columbian College of Arts and Sciences of The George Washington University in partial fulfillment of the requirements for the degree of Doctor of Philosophy August 31, 2017 Chet C. Sherwood Professor of Anthropology The Columbian College of Arts and Sciences of The George Washington University certifies that Laura D. Reyes has passed the Final Examination for the degree of Doctor of Philosophy as of May 3, 2017. This is the final and approved form of the dissertation. Tool-use and the Chimpanzee Brain: An Investigation of Gray and White Matter, and a Focused Study of Inferior Parietal Microstructure Laura Denise Reyes Dissertation Research Committee: Chet C. Sherwood, Professor of Anthropology, Dissertation Director Kimberley Phillips, Professor of Psychology, Trinity University, Committee Member Scott Mackey, Assistant Professor of Psychiatry, University of Vermont, Committee Member ii © Copyright 2017 by Laura Denise Reyes All rights reserved. iii Acknowledgments The author would like to thank her parents, Loretta and Francisco Reyes; her grandparents, Celia and Ralph Lopez and Paula and Francisco Reyes; and all of her family and friends who offered support during the course of her education, especially Amelia Villaseñor and Chrisandra Kufeldt. The author acknowledges the dissertation committee, Brenda Bradley (Chair), Chet Sherwood (Advisor), David Braun, Scott Mackey, Kimberley Phillips, and Sarah Shomstein, as well as the following funding sources: National Science Foundation Doctoral Dissertation Research Improvement Grant BCS-1455629 and GWU Provost’s Fellowship.
    [Show full text]
  • The Utility of Geometric Morphometrics to Elucidate Pathways of Cichlid Fish Evolution
    SAGE-Hindawi Access to Research International Journal of Evolutionary Biology Volume 2011, Article ID 290245, 8 pages doi:10.4061/2011/290245 Review Article The Utility of Geometric Morphometrics to Elucidate Pathways of Cichlid Fish Evolution Michaela Kerschbaumer and Christian Sturmbauer Department of Zoology, Karl-Franzens University of Graz, Universit¨atsplatz 2, 8010 Graz, Austria Correspondence should be addressed to Michaela Kerschbaumer, [email protected] Received 22 December 2010; Accepted 29 March 2011 Academic Editor: Tetsumi Takahashi Copyright © 2011 M. Kerschbaumer and C. Sturmbauer. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Fishes of the family Cichlidae are famous for their spectacular species flocks and therefore constitute a model system for the study of the pathways of adaptive radiation. Their radiation is connected to trophic specialization, manifested in dentition, head morphology, and body shape. Geometric morphometric methods have been established as efficient tools to quantify such differences in overall body shape or in particular morphological structures and meanwhile found wide application in evolutionary biology. As a common feature, these approaches define and analyze coordinates of anatomical landmarks, rather than traditional counts or measurements. Geometric morphometric methods have several merits compared to traditional morphometrics, particularly for the distinction and analysis of closely related entities. Cichlid evolutionary research benefits from the efficiency of data acquisition, the manifold opportunities of analyses, and the potential to visualize shape changes of those landmark-based methods. This paper briefly introduces to the concepts and methods of geometric morphometrics and presents a selection of publications where those techniques have been successfully applied to various aspects of cichlid fish diversification.
    [Show full text]
  • S41598-019-48446-0[1]
    Edinburgh Research Explorer Network analysis of canine brain morphometry links tumour risk to oestrogen deficiency and accelerated brain ageing Citation for published version: Rzechorzek, N, Saunders, O, Hiscox, L, Schwarz, T, Marioni-Henry, K, Argyle, D, Schoenebeck, J & Freeman, T 2019, 'Network analysis of canine brain morphometry links tumour risk to oestrogen deficiency and accelerated brain ageing', Scientific Reports. https://doi.org/10.1038/s41598-019-48446-0 Digital Object Identifier (DOI): 10.1038/s41598-019-48446-0 Link: Link to publication record in Edinburgh Research Explorer Document Version: Publisher's PDF, also known as Version of record Published In: Scientific Reports Publisher Rights Statement: Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. General rights Copyright for the publications made accessible via the Edinburgh Research Explorer is retained by the author(s) and / or other copyright owners and it is a condition of accessing these publications that users recognise and abide by the legal requirements associated with these rights.
    [Show full text]
  • A Practical Introduction to Landmark-Based Geometric Morphometrics
    A PRACTICAL INTRODUCTION TO LANDMARK-BASED GEOMETRIC MORPHOMETRICS MARK WEBSTER Department of the Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637 and H. DAVID SHEETS Department of Physics, Canisius College, 2001 Main Street, Buffalo, NY 14208 ABSTRACT.—Landmark-based geometric morphometrics is a powerful approach to quantifying biological shape, shape variation, and covariation of shape with other biotic or abiotic variables or factors. The resulting graphical representations of shape differences are visually appealing and intuitive. This paper serves as an introduction to common exploratory and confirmatory techniques in landmark-based geometric morphometrics. The issues most frequently faced by (paleo)biologists conducting studies of comparative morphology are covered. Acquisition of landmark and semilandmark data is discussed. There are several methods for superimposing landmark configu- rations, differing in how and in the degree to which among-configuration differences in location, scale, and size are removed. Partial Procrustes superimposition is the most widely used superimposition method and forms the basis for many subsequent operations in geometric morphometrics. Shape variation among superimposed con- figurations can be visualized as a scatter plot of landmark coordinates, as vectors of landmark displacement, as a thin-plate spline deformation grid, or through a principal components analysis of landmark coordinates or warp scores. The amount of difference in shape between two configurations can be quantified as the partial Procrustes distance; and shape variation within a sample can be quantified as the average partial Procrustes distance from the sample mean. Statistical testing of difference in mean shape between samples using warp scores as variables can be achieved through a standard Hotelling’s T2 test, MANOVA, or canonical variates analysis (CVA).
    [Show full text]
  • Changes in Cerebral Morphology Consequent to Peripheral Autonomic Denervation
    NeuroImage 18 (2003) 908–916 www.elsevier.com/locate/ynimg Changes in cerebral morphology consequent to peripheral autonomic denervation Hugo D. Critchley,a,b,* Catriona D. Good,a John Ashburner,a Richard S. Frackowiak,a Christopher J. Mathias,b,c and Raymond J. Dolana a Wellcome Department of Imaging Neuroscience, Institute of Neurology, UCL, 12 Queen Square, London WC1N 3BG, UK b Autonomic Unit, National Hospital for Neurology & Neurosurgery and Institute of Neurology, UCL, Queen Square, London WC1N 3BG, UK c Neurovascular Medicine Unit, St. Mary’s Hospital, ICSM, London W2 1NY, UK Received 14 June 2002; accepted 12 November 2002 Abstract Pure autonomic failure (PAF) is characterized by an acquired, selective, peripheral denervation of the autonomic nervous system. Patients with PAF fail to generate bodily states of arousal via the autonomic nervous system in response to physical or cognitive effort. We used voxel-based morphometry to test the hypothesis that changes in the morphology of brain regions involved in autonomic control would arise as a consequence to the longstanding absence of peripheral autonomic responses in PAF patients. Optimized voxel-based morphometry of structural magnetic resonance scans was used to test for regional differences in grey and white matter in 15 PAF patients and matched controls. There were no group differences observed in global measures of grey matter, white matter, or cerebrospinal fluid (CSF). We identified morphometric differences reflecting regional decreases in grey matter volume and concentration in anterior cingulate and insular cortices in PAF patients relative to controls. Morphometric differences in brainstem and subcortical regions did not reach statistical significance.
    [Show full text]
  • Systematic Morphology of Fishes in the Early 21St Century
    Copeia 103, No. 4, 2015, 858–873 When Tradition Meets Technology: Systematic Morphology of Fishes in the Early 21st Century Eric J. Hilton1, Nalani K. Schnell2, and Peter Konstantinidis1 Many of the primary groups of fishes currently recognized have been established through an iterative process of anatomical study and comparison of fishes that has spanned a time period approaching 500 years. In this paper we give a brief history of the systematic morphology of fishes, focusing on some of the individuals and their works from which we derive our own inspiration. We further discuss what is possible at this point in history in the anatomical study of fishes and speculate on the future of morphology used in the systematics of fishes. Beyond the collection of facts about the anatomy of fishes, morphology remains extremely relevant in the age of molecular data for at least three broad reasons: 1) new techniques for the preparation of specimens allow new data sources to be broadly compared; 2) past morphological analyses, as well as new ideas about interrelationships of fishes (based on both morphological and molecular data) provide rich sources of hypotheses to test with new morphological investigations; and 3) the use of morphological data is not limited to understanding phylogeny and evolution of fishes, but rather is of broad utility to understanding the general biology (including phenotypic adaptation, evolution, ecology, and conservation biology) of fishes. Although in some ways morphology struggles to compete with the lure of molecular data for systematic research, we see the anatomical study of fishes entering into a new and exciting phase of its history because of recent technological and methodological innovations.
    [Show full text]
  • Comparative Anatomy and Functional Morphology University of California at Berkeley Department of Integrative Biology (5 Units)
    Comparative Anatomy and Functional Morphology University of California at Berkeley Department of Integrative Biology (5 Units) Course Description: This course is an in-depth look at the biology of form and function. We will examine vertebrate anatomy to understand how structures develop, how they have evolved, and how they interact with one another to allow animals to live in a variety of environments. We will study the integration of the skeletal, muscular, nervous, vascular, respiratory, digestive, endocrine, and urogenital systems to explore the historical and present diversity of vertebrate animals. Format: This course will include lecture, discussion, and laboratory sessions. Lectures will focus primarily on broad concepts and ideas. Discussion sections will emphasize how to both read and analyze primary scientific literature. Laboratory sessions will allow students to physically explore the morphologies of a diversity of taxa and will include museum specimens as well as dissections of whole animals. Lecture: Monday, Tuesday, Wednesday, and Thursday, 9:30-11:00a.m. Discussion: Monday and Thursday, 11:00a.m. or 12:00p.m. Laboratory: Monday, Tuesday, Wednesday, and Thursday, 2:00-5:00p.m. All students must take lectures, discussion sections, and laboratory sections concurrently. Attendance of all sections is required. Goals: 1. A comparative approach will allow students to gain experience in identifying similarities and differences among taxa and further their understanding of how both evolutionary and environmental contexts influence the morphology and function. 2. Students will improve their ability to ask questions and answer them using scientific methodology. 3. Students will gain factual knowledge of terms and concepts regarding vertebrate anatomy and functional morphology.
    [Show full text]
  • Brain Morphometry in 22Q11.2 Deletion Syndrome: an Exploration of Diferences in Cortical Thickness, Surface Area, and Their Contribution to Cortical Volume M
    www.nature.com/scientificreports OPEN Brain morphometry in 22q11.2 deletion syndrome: an exploration of diferences in cortical thickness, surface area, and their contribution to cortical volume M. Gudbrandsen1, E. Daly1, C. M. Murphy1,2, C. E. Blackmore1,2, M. Rogdaki3,4, C. Mann5, A. Bletsch5, L. Kushan6, C. E. Bearden6,7, D. G. M. Murphy1, M. C. Craig1,8 & Christine Ecker1,5* 22q11.2 Deletion Syndrome (22q11.2DS) is the most common microdeletion in humans, with a heterogenous clinical presentation including medical, behavioural and psychiatric conditions. Previous neuroimaging studies examining the neuroanatomical underpinnings of 22q11.2DS show alterations in cortical volume (CV), cortical thickness (CT) and surface area (SA). The aim of this study was to identify (1) the spatially distributed networks of diferences in CT and SA in 22q11.2DS compared to controls, (2) their unique and spatial overlap, as well as (3) their relative contribution to observed diferences in CV. Structural MRI scans were obtained from 62 individuals with 22q11.2DS and 57 age- and-gender-matched controls (aged 6–31). Using FreeSurfer, we examined diferences in vertex-wise estimates of CV, CT and SA at each vertex, and compared the frequencies of vertices with a unique or overlapping diference for each morphometric feature. Our fndings indicate that CT and SA make both common and unique contributions to volumetric diferences in 22q11.2DS, and in some areas, their strong opposite efects mask diferences in CV. By identifying the neuroanatomic variability in 22q11.2DS, and the separate contributions of CT and SA, we can start exploring the shared and distinct mechanisms that mediate neuropsychiatric symptoms across disorders, e.g.
    [Show full text]
  • Bacterial Size, Shape and Arrangement & Cell Structure And
    Lecture 13, 14 and 15: bacterial size, shape and arrangement & Cell structure and components of bacteria and Functional anatomy and reproduction in bacteria Bacterial size, shape and arrangement Bacteria are prokaryotic, unicellular microorganisms, which lack chlorophyll pigments. The cell structure is simpler than that of other organisms as there is no nucleus or membrane bound organelles.Due to the presence of a rigid cell wall, bacteria maintain a definite shape, though they vary as shape, size and structure. When viewed under light microscope, most bacteria appear in variations of three major shapes: the rod (bacillus), the sphere (coccus) and the spiral type (vibrio). In fact, structure of bacteria has two aspects, arrangement and shape. So far as the arrangement is concerned, it may Paired (diplo), Grape-like clusters (staphylo) or Chains (strepto). In shape they may principally be Rods (bacilli), Spheres (cocci), and Spirals (spirillum). Size of Bacterial Cell The average diameter of spherical bacteria is 0.5- 2.0 µm. For rod-shaped or filamentous bacteria, length is 1-10 µm and diameter is 0.25-1 .0 µm. E. coli , a bacillus of about average size is 1.1 to 1.5 µm wide by 2.0 to 6.0 µm long. Spirochaetes occasionally reach 500 µm in length and the cyanobacterium Accepted wisdom is that bacteria are smaller than eukaryotes. But certain cyanobacteria are quite large; Oscillatoria cells are 7 micrometers diameter. The bacterium, Epulosiscium fishelsoni , can be seen with the naked eye (600 mm long by 80 mm in diameter). One group of bacteria, called the Mycoplasmas, have individuals with size much smaller than these dimensions.
    [Show full text]
  • Multivariate Allometry
    MULTIVARIATE ALLOMETRY Christian Peter Klingenberg Department of Biological Sciences University of Alberta Edmonton, Alberta T6G 2E9, Canada ABSTRACT The subject of allometry is variation in morphometric variables or other features of organisms associated with variation in size. Such variation can be produced by several biological phenomena, and three different levels of allometry are therefore distinguished: static allometry reflects individual variation within a population and age class, ontogenetic allometry is due to growth processes, and evolutionary allomctry is thc rcsult of phylogcnctic variation among taxa. Most multivariate studies of allometry have used principal component analysis. I review the traditional technique, which can be interpreted as a least-squares fit of a straight line to the scatter of data points in a multidimensional space spanned by the morphometric variables. I also summarize some recent developments extending principal component analysis to multiple groups. "Size correction" for comparisons between groups of organisms is an important application of allometry in morphometrics. I recommend use of Bumaby's technique for "size correction" and compare it with some similar approaches. The procedures described herein are applied to a data set on geographic variation in the waterstrider Gerris costae (Insecta: Heteroptera: Gcrridac). In this cxamplc, I use the bootstrap technique to compute standard errors and perform statistical tcsts. Finally, I contrast this approach to the study ofallometry with some alternatives, such as factor analytic and geometric approaches, and briefly analyze the different notions of allometry upon which these approaches are based. INTRODUCTION Variation in sizc of organisms usually is associated with variation in shape, and most mctric charactcrs arc highly corrclatcd among one another.
    [Show full text]
  • Morphometric Analysis of Brain in Newborn with Congenital Diaphragmatic Hernia
    brain sciences Article Morphometric Analysis of Brain in Newborn with Congenital Diaphragmatic Hernia Martina Lucignani 1, Daniela Longo 2, Elena Fontana 2, Maria Camilla Rossi-Espagnet 2,3, Giulia Lucignani 2, Sara Savelli 4, Stefano Bascetta 4, Stefania Sgrò 5, Francesco Morini 6, Paola Giliberti 6 and Antonio Napolitano 1,* 1 Medical Physics Department, Bambino Gesù Children’s Hospital, IRCCS, 00165 Rome, Italy; [email protected] 2 Neuroradiology Unit, Imaging Department, Bambino Gesù Children’s Hospital, IRCCS, 00165 Rome, Italy; [email protected] (D.L.); [email protected] (E.F.); [email protected] (M.C.R.-E.); [email protected] (G.L.) 3 NESMOS Department, Sant’Andrea Hospital, Sapienza University, 00189 Rome, Italy 4 Imaging Department, Bambino Gesù Children’s Hospital and Research Institute, 00165 Rome, Italy; [email protected] (S.S.); [email protected] (S.B.) 5 Department of Anesthesia and Critical Care, Bambino Gesù Children’s Hospital, IRCCS, 00165 Rome, Italy; [email protected] 6 Department of Medical and Surgical Neonatology, Bambino Gesù Children’s Hospital, IRCCS, 00165 Rome, Italy; [email protected] (F.M.); [email protected] (P.G.) * Correspondence: [email protected]; Tel.: +39-333-3214614 Abstract: Congenital diaphragmatic hernia (CDH) is a severe pediatric disorder with herniation of abdominal viscera into the thoracic cavity. Since neurodevelopmental impairment constitutes a common outcome, we performed morphometric magnetic resonance imaging (MRI) analysis on Citation: Lucignani, M.; Longo, D.; CDH infants to investigate cortical parameters such as cortical thickness (CT) and local gyrification Fontana, E.; Rossi-Espagnet, M.C.; index (LGI).
    [Show full text]
  • Fractal Dimension Brain Morphometry: a Novel Approach to Quantify White Matter in Traumatic Brain Injury
    Brain Imaging and Behavior (2019) 13:914–924 https://doi.org/10.1007/s11682-018-9892-2 ORIGINAL RESEARCH Fractal dimension brain morphometry: a novel approach to quantify white matter in traumatic brain injury Venkateswaran Rajagopalan1,2 & Abhijit Das2,3 & Luduan Zhang4 & Frank Hillary5 & Glenn R. Wylie2,3 & Guang H. Yue2,6 Published online: 16 June 2018 # Springer Science+Business Media, LLC, part of Springer Nature 2018 Abstract Traumatic brain injury (TBI) is the main cause of disability in people younger than 35 in the United States. The mechanisms of TBI are complex resulting in both focal and diffuse brain damage. Fractal dimension (FD) is a measure that can characterize morphometric complexity and variability of brain structure especially white matter (WM) structure and may provide novel insights into the injuries evident following TBI. FD-based brain morphometry may provide information on WM structural changes after TBI that is more sensitive to subtle structural changes post injury compared to conventional MRI measurements. Anatomical and diffusion tensor imaging (DTI) data were obtained using a 3 T MRI scanner in subjects with moderate to severe TBI and in healthy controls (HC). Whole brain WM volume, grey matter volume, cortical thickness, cortical area, FD and DTI metrics were evaluated globally and for the left and right hemispheres separately. A neuropsychological test battery sensitive to cognitive impairment associated with traumatic brain injury was performed. TBI group showed lower structural complexity (FD) bilaterally (p < 0.05). No significant difference in either grey matter volume, cortical thickness or cortical area was observed in any of the brain regions between TBI and healthy controls.
    [Show full text]